Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation??and Summary of Significant Accounting Policies - Narrative (Details)

v3.21.2
Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)
2 Months Ended 3 Months Ended 8 Months Ended 9 Months Ended 12 Months Ended
Jun. 10, 2021
USD ($)
Sep. 14, 2021
USD ($)
Sep. 30, 2021
segment
Sep. 30, 2020
USD ($)
segment
Sep. 14, 2021
USD ($)
plan
Sep. 30, 2021
USD ($)
segment
landfill
Sep. 30, 2020
USD ($)
segment
Dec. 31, 2020
USD ($)
Sep. 30, 2017
USD ($)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                  
Percent of revenue, ASC 606           82.00% 100.00%    
Percent of revenue, ASC 840           18.00%      
Number of operating landfill gas to electricity facilities | landfill           12      
Reporting segment | segment     2 2   2 2    
Mavrix                  
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                  
Earn-out payment           $ 1,700,000      
Mavrix | Maximum                  
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                  
Earn-out payment obligation                 $ 9,550,000
Aria Energy LLC                  
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                  
Percent of revenue, ASC 606         36.00%   42.00%    
Percent of revenue, ASC 840         64.00%   58.00%    
Reporting segment | plan         2        
Proceeds from sale of assets held for sale $ 58,500,000                
Gain on extinguishment of debt 61,400,000 $ 0   $ 0 $ 61,411,000   $ 0    
Net gain (loss) from sale of LESPH         67,300,000   (9,500,000)    
Gain (Loss) on Disposition of Business $ 1,300,000                
Aria Energy LLC | LESPH                  
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                  
Net gain (loss) from sale of LESPH         67,600,000   $ (9,600,000)    
Aria Energy LLC | Mavrix                  
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                  
Earn-out payment         1,700,000     $ 1,400,000  
Earn-out payment obligation   1,700,000     1,700,000     $ 1,400,000  
Aria Energy LLC | Mavrix | Maximum                  
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                  
Earn-out payment obligation   $ 9,550,000     $ 9,550,000        
3.75% Term Note | Senior notes                  
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                  
Debt instrument, interest rate     3.75%     3.75%      
4.47% Term Note | Senior notes                  
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                  
Debt instrument, interest rate     4.47%     4.47%